From patchwork Mon Apr 27 18:32:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 11513171 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6C5B41805 for ; Mon, 27 Apr 2020 18:32:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F98821707 for ; Mon, 27 Apr 2020 18:32:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="owOp2JvF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726522AbgD0Scg (ORCPT ); Mon, 27 Apr 2020 14:32:36 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:64687 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726517AbgD0Scf (ORCPT ); Mon, 27 Apr 2020 14:32:35 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588012354; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=AVtHSmM65NemhBiR570J5CFVZSoe+CaOJF5K6Fa9wIU=; b=owOp2JvFKLYQHkUZwQRM6QDDOZV76QxnEX9e1uCb+Xy0IpTIC13l9SBp6h1cR+Hm6EII/9Kd R2XwdfweK7ClHjxB0peLutj3bPYEOqiMyWoipTYfAuUE/n/bCtZNlNFFs3CuGyT0nqLsrBK8 KydZ33vHJg8HpdgT8qor71/ZNlc= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5ea7253e.7f19ca052fb8-smtp-out-n04; Mon, 27 Apr 2020 18:32:30 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id CDA4CC433F2; Mon, 27 Apr 2020 18:32:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.0 Received: from bbhatt-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: bbhatt) by smtp.codeaurora.org (Postfix) with ESMTPSA id 43DC5C433CB; Mon, 27 Apr 2020 18:32:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 43DC5C433CB Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=bbhatt@codeaurora.org From: Bhaumik Bhatt To: mani@kernel.org Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, hemantk@codeaurora.org Subject: [PATCH v1 3/8] bus: mhi: core: Read transfer length from an event properly Date: Mon, 27 Apr 2020 11:32:17 -0700 Message-Id: <1588012342-4995-4-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588012342-4995-1-git-send-email-bbhatt@codeaurora.org> References: <1588012342-4995-1-git-send-email-bbhatt@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Hemant Kumar When MHI Driver receives an EOT event, it reads xfer_len from the event in the last TRE. The value is under control of the MHI device and never validated by Host MHI driver. The value should never be larger than the real size of the buffer but a malicious device can set the value 0xFFFF as maximum. This causes device to memory overflow (both read or write). Fix this issue by reading minimum of transfer length from event and the buffer length provided. Signed-off-by: Hemant Kumar --- drivers/bus/mhi/core/main.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index ba8afa7..196908d0 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -521,7 +521,10 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, mhi_cntrl->unmap_single(mhi_cntrl, buf_info); result.buf_addr = buf_info->cb_buf; - result.bytes_xferd = xfer_len; + + /* truncate to buf len if xfer_len is larger */ + result.bytes_xferd = + min_t(u16, xfer_len, buf_info->len); mhi_del_ring_element(mhi_cntrl, buf_ring); mhi_del_ring_element(mhi_cntrl, tre_ring); local_rp = tre_ring->rp;